Method of and apparatus for processing an input text, method of and apparatus for performing an approximate translation and storage medium

Abstract

A method of processing an input text comprising a plurality of words is provided. The method comprising the steps of deriving from the input text a plurality of sets such that each set comprises at least one of the words of the input text, all of the words of each set are present in the input text, and the words of each if any set containing more than one word constitute a collocation; assigning to each set a unique relative rank; comparing each set in order of decreasing relative rank with the input text; and selecting each set, all of whose words are present in the input text and none of whose words is present in a previously selected set of higher relative rank.

What is claimed is:  
     
       1. A method of processing an input text comprising a plurality of words, the method comprising the steps of: 
       deriving from the input text a plurality of sets such that each set comprises at least one of the words of the input text, all of the words of each set are present in the input text, and the words of each if any set containing more than one word constitute a collocation;  
       assigning to each set a unique relative rank;  
       comparing each set in order of decreasing relative rank with the input text; and  
       selecting each set, all of whose words are present in the input text and none of whose words is present in a previously selected set of higher relative rank.  
     
     
       2. A method as claimed in  claim 1 , wherein each of the words of the input text is present in at least one of the sets. 
     
     
       3. A method as claimed in  claim 1 , wherein all of the words of the input text are present in the union of the selected sets. 
     
     
       4. A method as claimed in  claim 1 , wherein the input text comprises a grammatically complete sample of text. 
     
     
       5. A method as claimed in  claim 1 , wherein the words comprise basic word forms derived from an original text by linguistic analysis in a preliminary step. 
     
     
       6. A method as claimed in  claim 1 , wherein the assigning step comprises a first step of assigning a priority value which increases with increasing number of words in the set. 
     
     
       7. A method as claimed in  claim 1 , wherein the assigning step comprises a second step of assigning a priority value which decreases with increasing span of the words of the set in the input text. 
     
     
       8. A method as claimed in  claim 6  wherein the assigning step comprises a second step of assigning a priority value which decreases with increasing span of the words of the set in the input text, wherein the second step is performed only if the first step results in more than one set having the same priority value. 
     
     
       9. A method as claimed in  claim 1 , wherein the assigning step comprises a third step of assigning a priority value which is dependent on the linguistic relationship between at least one word of the set and at least one word of the input text not in the set. 
     
     
       10. A method as claimed in  claim 7 , wherein the assigning step comprises a third step of assigning a priority value which is dependent on the linguistic relationship between at least one word of the set and at least one word of the input text not in the set, wherein the third step is performed only if the second step results in more than one set having the same priority value. 
     
     
       11. A method as claimed in  claim 1 , wherein the assigning step comprises a fourth step of assigning a priority value which increases with position to the right in the input text of the right-most word of the set. 
     
     
       12. A method as claimed in  claim 9 , wherein the assigning step comprises a fourth step of assigning a priority value which increases with position to the right in the input text of the right-most word of the set, wherein the fourth step is performed only if the third step results in more than one set having the same priority value. 
     
     
       13. A method as claimed in  claim 1 , wherein the assigning step comprises a fifth step of assigning priority value by default. 
     
     
       14. A method as claimed in  claim 11 , wherein the assigning step comprises a fifth step of assigning priority value by default, wherein the fifth step is performed only if the fourth step results in more than one set having the same priority value. 
     
     
       15. A method as claimed in claims  1 , wherein the assigning step comprises assigning a priority value based on a measure of probability for each set. 
     
     
       16. A method as claimed in  claim 1 , further comprising accessing an index of word sets with at least one of the selected sets. 
     
     
       17. An apparatus for processing an input text comprising a plurality of words, the apparatus comprising: 
       means for deriving from the input text a plurality of sets such that each set comprises at least one of the words of the input text, all of the words of each set are present in the input text, and the words of each if any set containing more than one word constitute a collocation;  
       means for assigning to each set a unique relative rank;  
       means for comparing each set in order of decreasing relative rank with the input text; and  
       means for selecting each set, all of whose words are present in the input text and none of whose words is present in a previously selected set of higher relative rank.  
     
     
       18. An apparatus as claimed in  claim 17 , wherein the deriving means is arranged such that each of the words of the input text is present in at least one of the sets. 
     
     
       19. An apparatus as claimed in  claim 17 , wherein the selecting means is arranged such that all of the words of the input text are present in the union of the selected sets. 
     
     
       20. An apparatus as claimed in  claim 17 , wherein the input text comprises a grammatically complete sample of text. 
     
     
       21. An apparatus as claimed in  claim 17 , wherein the words comprise basic word forms and the apparatus comprises a linguistic analyzer for analyzing an original text and providing the basic word forms. 
     
     
       22. An apparatus as claimed in  claim 17 , wherein the assigning means comprises first means for assigning a priority value which increases with increasing number of words in the set. 
     
     
       23. An apparatus as claimed in  claim 17 , wherein the assigning means comprises second means for assigning a priority value which decreases with increasing span of the words of the set in the input text. 
     
     
       24. An apparatus as claimed in  claim 22 , wherein the assigning means comprises second means for assigning a priority value which decreases with increasing span of the words of the set in the input text, wherein the second means is enabled only if the first means assigns the same priority value to more than one set. 
     
     
       25. An apparatus as claimed in  claim 17 , wherein the assigning means comprises third means for assigning a priority value which is dependent on the linguistic relationship between at least one word of the set and at least one word of the input text not in the set. 
     
     
       26. An apparatus as claimed in  claim 23 , wherein the assigning means comprises third means for assigning a priority value which is dependent on the linguistic relationship between at least one word of the set and at least one word of the input text not in the set, wherein the third means is enabled only if the second means assigns the same priority value to more than one set. 
     
     
       27. An apparatus as claimed in  claim 17 , wherein the assigning means comprises fourth means for assigning a priority value which increases with position to the tight in the input text of the right-most word of the set. 
     
     
       28. An apparatus as claimed in  claim 25 , wherein the assigning means comprises fourth means for assigning a priority value which increases with position to the right in the input text of the right-most word of the set, wherein the fourth means is enabled only if the third means assigns the same priority value to more than one set. 
     
     
       29. An apparatus as claimed in  claim 17 , wherein the assigning means comprises a fifth means for assigning a priority value by default. 
     
     
       30. An apparatus as claimed in  claim 27 , wherein the assigning means comprises a fifth means for assigning a priority value by default, wherein the fifth means is enabled only if the fourth means assigns the same priority value to more than one set. 
     
     
       31. An apparatus as claimed in  claim 17 , wherein the assigning means is arranged to assign a priority value based on a measure of probability for each set. 
     
     
       32. An apparatus as claimed in  claim 17 , further comprising a store containing an index of word sets and means for accessing the index with at least one of the selected sets. 
     
     
       33. An apparatus as claimed in  claim 17 , further comprising a programmed data processor. 
     
     
       34. A storage medium containing a program for a data processor of an apparatus as claimed in  claim 33 . 
     
     
       35. A method of performing an approximate translation of an input text in a first natural language to a second natural language, comprising performing a method as claimed in  claim 16 , wherein the index is a dictionary, and outputting dictionary entries in the second language corresponding to the selected sets. 
     
     
       36. An apparatus for performing approximate translation from an input text in a first natural language to a second natural language, comprising an apparatus as claimed in  claim 32 , the store containing entries constituting a dictionary.